1. Field of the Invention
The present invention relates to a color diffusion transfer photographic light-sensitive material and, more particularly, it relates to a color diffusion transfer photographic light-sensitive material containing a novel dye developer.
2. Description of the Prior Art
Using a dye developer to obtain a diffusion transfer image is known. A dye developer is a dye which possesses in the dye molecule a group capable of developing exposed silver halide. A typical example of such a group capable of developing exposed silver halide is a hydroquinonyl group. This dye developer is soluble in an alkali solution but, upon being oxidized through the development of the exposed silver halide, it becomes alkali solution-insoluble.
The principle of obtaining diffusion transfer images using such a dye developer is as follows. That is, when a dye developer-containing silver halide light-sensitive material is processed, after imagewise exposure, with an alkali-containing processing solution to thereby develop the silver halide in the negative material with the dye developer, the dye developer located at the exposed areas becomes insoluble upon development of the silver halide, while the dye developer located at the unexposed areas remains alkali solution-soluble. Therefore, when a positive material having a dye-receiving layer is superposed on the negative material, the alkali solution-soluble dye developer migrates into the positive layer to form a positive image.
Therefore, in order to obtain faithful color reproduction of the transferred images, the dye developers to be transferred must have excellent absorbance characteristics. That is, in reproducing natural color by the combination of three dye developers which respectively absorb the three primary colors of blue, green and red, too much overlap of the absorption curves of the respective three dyes is not preferable and, conversely, too large a gap (separation) of the absorption curves is not preferable, either. In other words, it is desirable that the absorption curve shows an absorption maximum at a certain desirable wavelength and shows a sharp drop as the wavelength shifts to the side of the adjacent absorption curve of the other dye.
With a yellow dye, poor visual sensitivity results with an absorption maximum at a wavelength which is too short, while the images are reddish with an absorption maximum at a wavelength which is too long.